C. II. Maryott — Halogens in Benzol Derivatives. 379 



carried out in an Erlenine^'er flask, and very little heating was 

 required so that a plain glass tube about 50™' in length, with- 

 out water cooling, served as a condenser. 



The test analyses given below were carried out as follows : 

 The substance was weighed out in the Erlenmeyer flask, 

 10-15'^'' of the alcohol-benzol mixture added, and the potassium, 

 in small pieces, gradually dropped in through the tube. The 

 weight of potassium required was about ten times* that called 

 for by the equation 



C,IT,Cl -f 2K + C,H,0H = C„H, + KCl + C^H^K. 



A small amount of potassium ethylate usually separated out 

 during the action of the metal, but seemed to have no bad 

 effect upon the reduction. After the action had become less 

 vigorous, about 2"^^^ of alcohol were added, the flask carefully 

 heated and gently shaken from time to time until the potassium 

 was all dissolved. The contents were then shaken with water, 

 the water layer acidified with nitric acid, and the halogen 

 precipitated and weighed as the silver salt. The use of 

 Volhard's volumetric method in estimating the halogens, as 

 done by Stephanoff and Bacon, would, of course, have been 

 feasible, though somewhat less accurate. The time required 

 for an analysis, exclusive of weighings, was about twenty-five 

 minutes. 



A series of analyses gave the following results : 



Chloebenzol, 31-52 per cent Chlorine. 





Weight taken 



Per cent of 









grm. 



chlorine found 



Per cent error 



(0 



•4036 



81 62 



+ 



•1 



(2) 



•35:{3 



31 -40 



— 



•06 



(») 



•4181 



3r5l 



— 



•01 



(4) 



•3278 



31-44 



— ■ 



•08 



(5) 



•4087 



31 -48 



— 



•04 



(6) 



•4245 



31-53 



^- 



•01 



(V) 



•3324 



31^52 



± 



•0 



(8) 



•3530 



30^39 



1^13 



With the exception of No. (8) the agreement is satisfac- 

 tory. The low result here is doubtless due to the use of an 

 insufficient amount of potassium, as only six times that required 

 by theory was added. The chlorbenzol was twice redistilled 

 and that portion distilling between 131^5° and 131-7° used in 

 the analyses. 



* StephanofE's method calls for twenty-five times the theoretical amount 

 of sodium. 



